Effects Of Catecholamines Research Articles

THE SELECTIVE DELETION OF TYROSYNE HYDROXYLASE GENE IN THE ENDOTHELIUM AFFECTS CARDIOVASCULAR FUNCTION

Objective: We showed that the endothelium can synthesize and release catecholamines in response to hypoxia. However, the pathophysiological implications of such findings are still unknown since no mouse model is available to achieve this goal. The aim of the study is the generation and characterization of a transgenic mouse model in which the tyrosine hydroxylase (TH) gene is selectively deleted in the endothelium. Design and method: The animal model was generated using the CRE-LOX system with specific tissue expression of the CRE recombinase. TH-FLOX mice and Tie2-CRE mice were crossed to obtain mice with endothelial knock-out of the TH gene (TH - / -). The level of circulating CA was assessed by ELISA assay. We measured blood pressure with a non-invasive method (CODA Tail-Cuff). In vitro, TH gene was deleted in mouse endothelial cells by a specific siRNA to evaluate its effects on endothelial function. Results: The level of circulating catecholamines is significantly reduced in TH -/- mice compared to TH +/+ mice, suggesting a key role of the endothelium in the production of circulating CAs. We evaluated blood pressure levels and found a significant increase in TH -/- young mice compared to TH +/+ mice. In vitro, we evaluated the effects of TH deletion on endothelial function. The deletion induced a significant reduction of nitric oxide, angiogenesis on Matrigel, and an increase in apoptosis and inflammatory cytokines suggesting an autocrine effect of catecholamines produced by the endothelium. Conclusions: These data indicate that the reduced production of endothelial CA alters vascular function, suggesting that endothelial catecholamines are essential for the proper functioning of the cardiovascular system.

Neighborhood socioeconomic deprivation and individual-level socioeconomic status are associated with dopamine-mediated changes to monocyte subset CCR2 expression via a cAMP-dependent pathway

Social determinants of health (SDoH) include socioeconomic, environmental, and psychological factors that impact health. Neighborhood socioeconomic deprivation (NSD) and low individual-level socioeconomic status (SES) are SDoH that associate with incident heart failure, stroke, and cardiovascular mortality, but the underlying biological mechanisms are not well understood. Previous research has demonstrated an association between NSD, in particular, and key components of the neural-hematopoietic-axis including amygdala activity as a marker of chronic stress, bone marrow activity, and arterial inflammation. Our study further characterizes the role of NSD and SES as potential sources of chronic stress related to downstream immunological factors in this stress-associated biologic pathway. We investigated how NSD, SES, and catecholamine levels (as proxy for sympathetic nervous system activation) may influence monocytes which are known to play a significant role in atherogenesis. First, in an ex vivo approach, we treated healthy donor monocytes with biobanked serum from a community cohort of African Americans at risk for CVD. Subsequently, the treated monocytes were subjected to flow cytometry for characterization of monocyte subsets and receptor expression. We determined that NSD and serum catecholamines (namely dopamine [DA] and norepinephrine [NE]) associated with monocyte C–C chemokine receptor type 2 (CCR2) expression (p < 0.05), a receptor known to facilitate recruitment of monocytes towards arterial plaques. Additionally, NSD associated with catecholamine levels, especially DA in individuals of low SES. To further explore the potential role of NSD and the effects of catecholamines on monocytes, monocytes were treated in vitro with epinephrine [EPI], NE, or DA. Only DA increased CCR2 expression in a dose-dependent manner (p < 0.01), especially on non-classical monocytes (NCM). Furthermore, linear regression analysis between D2-like receptor surface expression and surface CCR2 expression suggested D2-like receptor signaling in NCM. Indicative of D2-signaling, cAMP levels were found to be lower in DA-treated monocytes compared to untreated controls (control 29.78 pmol/ml vs DA 22.97 pmol/ml; p = 0.038) and the impact of DA on NCM CCR2 expression was abrogated by co-treatment with 8-CPT, a cAMP analog. Furthermore, Filamin A (FLNA), a prominent actin-crosslinking protein, that is known to regulate CCR2 recycling, significantly decreased in DA-treated NCM (p < 0.05), indicating a reduction of CCR2 recycling. Overall, we provide a novel immunological mechanism, driven by DA signaling and CCR2, for how NSD may contribute to atherogenesis. Future studies should investigate the importance of DA in CVD development and progression in populations disproportionately experiencing chronic stress due to SDoH.

PO-02-147 THE ANTIARRHYTHMIC EFFECTS OF MIRABEGRON IN ISOLATED RABBIT HEARTS

β-3 adrenoceptor (AR) activation opposes the effects of β-1 and β-2 AR activation and rescues the effects of excessive catecholamines. BRL37344 (beta3-AR agonist) is antiarrhythmic in canine models. Mirabegron is a β-3 agonist approved by the FDA for the treatment of overactive bladder. A previous study showed that isoproterenol activates the small conductance Ca-activated K current more in female than in male ventricles. To test the hypothesis that mirabegron reduces the proarrhythmic effects of isoproterenol more effectively in female than in male ventricles. We performed optical mapping studies in 6 male and 6 female Langendorff-perfused rabbit hearts first at baseline, then sequentially after isoproterenol (ISO, 100 nM), mirabegron (1000 nM), apamin (100 nM) administration and washout in study 1. In study 2 (5 males and 5 females), we studied at baseline, then after adding mirabegron (250 nM, 500 nM, 750 nM, and 1000 nM), followed by isoproterenol and washout. All hearts underwent 10 attempts of ventricular fibrillation (VF) induction with a ventricular burst (20 Hz for 10 s) pacing at each stage of the experiment. The number of phase singularities (PSs) was determined per episode of VF (PSs/VF). In study 1, mirabegron reduced the VF inducibility (number of VF after 10 attempts) during isoproterenol infusion by an average of -2.75 (p = 0.026). When VF was induced, the PSs/VF increased by 2.4±2.1 in males and 6.6±3.3 in females (p=0.03, Figure A). Mirabegron significantly reduced the PSs/VF in both sexes and eliminated the sex differences. Apamin given after mirabegron in the presence of isoproterenol did not further change PSs/VF (p=0.63) (Figure B). The conduction velocity (CV), estimated by the inverse of the total activation time (1/s), was 16±2.7 for all hearts at baseline and 35±10 after ISO, respectively (p=0.0006). ISO did not increase CV differentially by sex (p=0.93). Mirabegron reduced the CV by an average of 15.6 (from 34±11.4 to 18±3.9) in females, which was significantly (p=0.043) more than 5.1 (from 35±8.7 to 31±9.3) in males. Figure C shows a summary of study 2. Mirabegron significantly reduced PSs/VF at 750 nM in female (p=0.015 vs. baseline) and at 1000 nM in male (p=0.033 vs. baseline) hearts. The addition of ISO did not increase PSs/VF. During ISO infusion, mirabegron reduces the CV and the PSs/VF more in females than males during VF. These data suggest that the β3 agonist is a sex-specific antiarrhythmic agent.

Investigating potential modifier genes of chronic PKA activation in heart failure

The cAMP-dependent protein kinase (PKA) is a major downstream effector of β-adrenergic signaling responsible for the positive inotropic effect of catecholamines. The PKA holoenzyme is a heterotetramer composed of two catalytic (C) and two regulatory (R) subunits. Three C subunits (Cα, Cβ and Cγ) are coded by three genes and four R subunits (RIα, RIβ, RIIα and RIIβ) are encoded by four genes but the heart expresses predominantly Cα, RIα and RIIα. We have shown that conditional knock-out of RIα in cardiomyocytes from adult mice (RIα-icKO) have constitutive PKA activation and spontaneously develop heart failure with reduced ejection fraction (HFrEF) upon aging, resulting in 50% mortality after 1 year (Bedioune et al. submitted). In this work, we aimed to better characterize the HF phenotype of RIα-icKO mice. We performed echocardiography, RT-qPCR, western blot and bulk RNA sequencing in RIα-icKO mice and control littermates at 1 year of age. We show that the HF phenotype of the surviving RIα-icKO mice at 1 year is heterogeneous: among 51 mice analyzed by echocardiography and gravimetry, 23 (45%) showed clear signs of HF (EF < 50%, cardiac hypertrophy and dilatation, lung congestion, named HFKO), whereas 18 (35%) had none (named NFKO) and 10 had an intermediary phenotype (20%). RIα residual expression and PKA activity appeared similar in HFKO (n = 6–9) and NFKO (n = 6–10) Transcriptomic analysis revealed dysregulation of typical HF marker genes in NFKO that was generally exacerbated in HFKO. Gene ontology analysis also showed TOP 10 up-regulated and down-regulated pathways classically associated with HF that were similar in HFKO and NFKO. A total of 542 genes were differentially expressed (fc 1.5, P < 0.05) between HFKO and NFKO. Cross-referencing with a list of 821 genes containing genes associated with HF from NCBI and components of β-AR signaling yielded 35 differentially expressed genes, among which 9 were selected as potential modifiers of the phenotype based on the literature. Our results suggest that NFKO represent a compensated stage of HF development. Comparison with HFKO identified new genes that could modulate the impact of chronic PKA activation on HF development. Further studies are required to identify other potential candidates and validate them in neonatal cardiomyocytes with chronic PKA activation.

Signatures of Co-Deregulated Genes and Their Transcriptional Regulators in Kidney Cancers.

There are several studies on the deregulated gene expression profiles in kidney cancer, with varying results depending on the tumor histology and other parameters. None of these, however, have identified the networks that the co-deregulated genes (co-DEGs), across different studies, create. Here, we reanalyzed 10 Gene Expression Omnibus (GEO) studies to detect and annotate co-deregulated signatures across different subtypes of kidney cancer or in single-gene perturbation experiments in kidney cancer cells and/or tissue. Using a systems biology approach, we aimed to decipher the networks they form along with their upstream regulators. Differential expression and upstream regulators, including transcription factors [MYC proto-oncogene (MYC), CCAAT enhancer binding protein delta (CEBPD), RELA proto-oncogene, NF-kB subunit (RELA), zinc finger MIZ-type containing 1 (ZMIZ1), negative elongation factor complex member E (NELFE) and Kruppel-like factor 4 (KLF4)] and protein kinases [Casein kinase 2 alpha 1 (CSNK2A1), mitogen-activated protein kinases 1 (MAPK1) and 14 (MAPK14), Sirtuin 1 (SIRT1), Cyclin dependent kinases 1 (CDK1) and 4 (CDK4), Homeodomain interacting protein kinase 2 (HIPK2) and Extracellular signal-regulated kinases 1 and 2 (ERK1/2)], were computed using the Characteristic Direction, as well as GEO2Enrichr and X2K, respectively, and further subjected to GO and KEGG pathways enrichment analyses. Furthermore, using CMap, DrugMatrix and the LINCS L1000 chemical perturbation databases, we highlight putative repurposing drugs, including Etoposide, Haloperidol, BW-B70C, Triamterene, Chlorphenesin, BRD-K79459005 and β-Estradiol 3-benzoate, among others, that may reverse the expression of the identified co-DEGs in kidney cancers. Of these, the cytotoxic effects of Etoposide, Catecholamine, Cyclosporin A, BW-B70C and Lasalocid sodium were validated in vitro. Overall, we identified critical co-DEGs across different subtypes in kidney cancer, and our results provide an innovative framework for their potential use in the future.

Effect of stress on the chronotropic and inotropic responses to β-adrenergic agonists in isolated atria of KOβ2 mice

Altered sensitivity to the chronotropic and inotropic effects of catecholamines and reduction in β1/β2-adrenoceptor (β1/β2–AR) ratio were reported in failing and in senescent human heart, as well as in isolated atria and ventricle of rats submitted to stress. This was due to downregulation of β1-AR with or without up-regulation of β2-AR. AimsTo investigate the stress-induced behavior of β1-AR in the heart of mice expressing a non-functional β2-AR subtype. The guiding hypothesis is that the absence of β2-AR signaling will not affect the behavior of β1-AR during stress and that those are independent processes. Materials and methodsThe chronotropic and inotropic responses to β-AR agonists in isolated atria of stressed mice expressing a non-functional β2-AR were analyzed. The mRNA and protein expressions of β1- and β2–AR were also determined. Key findingsNo deaths were observed in mice under stress protocol. Atria of stressed mice displayed reduced sensitivity to isoprenaline compared to the controls, an effect that was abolished by the β2- and β1-AR antagonists 50 nM ICI118,551 and 300 nM CGP20712A, respectively. Sensitivity and maximum response to the β-agonists dobutamine and salbutamol were not altered by stress or ICI118,551. The responses to dobutamine and salbutamol were prevented by CGP20712A. The expression of β1-AR was reduced at protein levels. SignificanceCollectively, our data provide evidence that the cardiac β2-AR is not essential for survival in a stressful situation and that the stress-induced reduction of β1-AR expression was independent of the β2-AR presence.

Stress Cardiomyopathy (Takotsubo Cardiomyopathy)

In this article we describe a rare clinical condition of stress cardiomyopathy (takotsubo cardiomyopathy) for which we, despite controversy and lack of data, identified the main pathogenic pathways (including the direct toxic effect of catecholamines on the myocardium, catecholamine-mediated myocardial stunning, and microcirculation disorders). After the systematic review, we identified the distinct pathology features of this condition and new diagnostic strategies.

Running from a Bear: How We Teach Vasopressors, Adrenoreceptors, and Shock.

Vasopressors are widely used in the management of shock among critically ill patients. The physiology of vasopressors and adrenoreceptors and their effects on end organs therefore represent important, high-yield topics for learners in the critical care environment. In this report, we describe our approach to teaching this core concept using the stereotypical human physiologic response when running from a bear, in the context of the relevant supporting literature. We use escaping from a threatening predator as a lens to describe the end-organ effects of activating adrenoreceptors together with the effects of endogenous and exogenous catecholamines and vasopressors. After reviewing this foundational physiology, we transition to the clinical environment, reviewing the pathophysiology of various shock states. We then consolidate our teaching by integrating the physiology of adrenoreceptors with the pathophysiology of shock to understand the appropriateness of each therapy to various shock phenotypes. We emphasize to learners the importance of generating a hypothesis about a patient's physiology, testing that hypothesis with an intervention, and then revising the hypothesis as needed, a critical component in the management of critically ill patients.

Long-term prognostic impact of beta-blockers in patients with Takotsubo syndrome: Results from the RETAKO Registry

BackgroundNo evidence-based therapy has yet been established for Takotsubo syndrome (TTS). Given the putative harmful effects of catecholamines in patients with TTS, beta-blockers may potentially decrease the intensity of the detrimental cardiac effects in those patients. ObjectiveThe purpose of this study was to assess the impact of beta-blocker therapy on long-term mortality and TTS recurrence. MethodsThe cohort study used the national Spanish Registry on TakoTsubo Syndrome (RETAKO). A total of 970 TTS post-discharge survivors, without pheochromocytoma, left ventricular outflow tract obstruction, sustained ventricular arrhythmias, and significant bradyarrhythmias, between January 1, 2003, and July 31, 2018, were assessed. Cox regression analysis and inverse probability weighting (IPW) propensity score analysis were used to evaluate the association between beta-blocker therapy and survival free of TTS recurrence. ResultsFrom 970 TTS patients, 582 (60.0%) received beta-blockers. During a mean follow-up of 2.5±3.3 years, there were 87 deaths (3.6 per 100 patients/year) and 29 TTS recurrences (1.2 per 100 patient/year). There was no significant difference in follow-up mortality or TTS recurrence in unadjusted and adjusted Cox analysis (hazard ratio [HR] 0.86, 95% confidence interval [CI] 0.59–1.27, and 0.95, 95% CI 0.57–1.13, respectively). After weighting and adjusting by IPW, differences in one-year survival free of TTS recurrence between patients treated and untreated with beta-blockers were not found (average treatment effect −0.01, 95% CI −0.07 to 0.04; p=0.621). ConclusionsIn this observational nationwide study from Spain, there was no significant association between beta-blocker therapy and follow-up survival free of TTS recurrence.

Catecholamine induces Kupffer cell apoptosis via growth differentiation factor 15 in alcohol-associated liver disease

Chronic alcohol consumption often induces hepatic steatosis but rarely causes severe inflammation in Kupffer cells (KCs) despite the increased hepatic influx of lipopolysaccharide (LPS), suggesting the presence of a veiled tolerance mechanism. In addition to LPS, the liver is affected by several gut-derived neurotransmitters through the portal blood, but the effects of catecholamines on KCs have not been clearly explored in alcohol-associated liver disease (ALD). Hence, we investigated the regulatory roles of catecholamine on inflammatory KCs under chronic alcohol exposure. We discovered that catecholamine levels were significantly elevated in the cecum, portal blood, and liver tissues of chronic ethanol-fed mice. Increased catecholamines induced mitochondrial translocation of cytochrome P450 2E1 in perivenous hepatocytes expressing the β2-adrenergic receptor (ADRB2), leading to the enhanced production of growth differentiation factor 15 (GDF15). Subsequently, GDF15 profoundly increased ADRB2 expression in adjacent inflammatory KCs to facilitate catecholamine/ADRB2-mediated apoptosis. Single-cell RNA sequencing of KCs confirmed the elevated expression of Adrb2 and apoptotic genes after chronic ethanol intake. Genetic ablation of Adrb2 or hepatic Gdf15 robustly decreased the number of apoptotic KCs near perivenous areas, exacerbating alcohol-associated inflammation. Consistently, we found that blood and stool catecholamine levels and perivenous GDF15 expression were increased in patients with early-stage ALD along with an increase in apoptotic KCs. Our findings reveal a novel protective mechanism against ALD, in which the catecholamine/GDF15 axis plays a critical role in KC apoptosis, and identify a unique neuro-metabo-immune axis between the gut and liver that elicits hepatoprotection against alcohol-mediated pathogenic challenges.

ANESTHESIOLOGY IN THE LIGHT OF THE TRANSFORMATIONS OF THE THEORY OF STRESS AND ADAPTATION. PERSPECTIVE OR SKEPTICISM OF PRACTICAL USE? (literature review)

The article attempts to analyze the main modern transformations of the theory of stress and adaptation and the possibility of implementing anti-stress adaptation reactions of general anesthesia. One of the central non-specific mechanisms of stressor injury has been found to be the stimulation of free-radical processes as a result of the often concomitant hypoxemia / hypoxia and the prooxidant effects of catecholamines. Data on the regulatory and adaptive effect of FR products (AOS and nitrogen) in the regulation of gene expression and increased production of antistress proteins, stimulation of mitochondrial biogenesis and normalization of energy metabolism are presented. The discussions of the "apologists" of adaptology about the "integral" indicators of the type of adaptation and the functional state of the organism are given. Emphasis is placed on the anesthesiologist's understanding that the organism is a relatively open selforganizing and self-structured dissipative system, as well as a critical view of the mathematical method of evaluating adaptation processes in the organism.

Neuroendocrine mechanisms in oxaliplatin-induced hyperalgesic priming.

Stress plays a major role in the symptom burden of oncology patients and can exacerbate cancer chemotherapy-induced peripheral neuropathy (CIPN), a major adverse effect of many classes of chemotherapy. We explored the role of stress in the persistent phase of the pain induced by oxaliplatin. Oxaliplatin induced hyperalgesic priming, a model of the transition to chronic pain, as indicated by prolongation of hyperalgesia produced by prostaglandin E 2 , in male rats, which was markedly attenuated in adrenalectomized rats. A neonatal handling protocol that induces stress resilience in adult rats prevented oxaliplatin-induced hyperalgesic priming. To elucidate the role of the hypothalamic-pituitary-adrenal and sympathoadrenal neuroendocrine stress axes in oxaliplatin CIPN, we used intrathecally administered antisense oligodeoxynucleotides (ODNs) directed against mRNA for receptors mediating the effects of catecholamines and glucocorticoids, and their second messengers, to reduce their expression in nociceptors. Although oxaliplatin-induced hyperalgesic priming was attenuated by intrathecal administration of β 2 -adrenergic and glucocorticoid receptor antisense ODNs, oxaliplatin-induced hyperalgesia was only attenuated by β 2 -adrenergic receptor antisense. Administration of pertussis toxin, a nonselective inhibitor of Gα i/o proteins, attenuated hyperalgesic priming. Antisense ODNs for Gα i 1 and Gα o also attenuated hyperalgesic priming. Furthermore, antisense for protein kinase C epsilon, a second messenger involved in type I hyperalgesic priming, also attenuated oxaliplatin-induced hyperalgesic priming. Inhibitors of second messengers involved in the maintenance of type I (cordycepin) and type II (SSU6656 and U0126) hyperalgesic priming both attenuated hyperalgesic priming. These experiments support a role for neuroendocrine stress axes in hyperalgesic priming, in male rats with oxaliplatin CIPN.

What is the effect of catecholamines on diastolic function in patients with pheochromocytoma and paraganglioma?

Pheochromocytoma is a rare form of secondary hypertension characterized by excessive production of catecholamines typically due to a benign tumor in the adrenal medulla. Among the potential cardiac repercussions of pheochromocytoma and paraganglioma, previous studies described echocardiographic abnormalities such as dynamic left ventricular outflow tract obstruction (i), cardiomyopathy (ii, iii, iv), reversible dilatation of the left ventricle (v) and left ventricular functional changes (vi) in patients with pheochromocytoma.

The Role of Adrenoreceptors and Calcium Ions in the Pathogenesis of Endocardium Endothelium Damage of Rats Under Stress Action on the Background of Hypercholesterolemia

Abstract. Topicality. Endothelial dysfunction is a key link in the pathogenesis, formation and progression of clinical manifestations of a significant number of cardiovascular system diseases. Some pathogenetic links and structures associated with morphofunctional disorders of cardiac endothelial cells under the stress conditions and its combination with hypercholesterolemia need further examination.&#x0D; The aim of the study was to investigate the role of adrenoreceptors and calcium ions (by using of adrenoreceptors and Ca2+-channels blockers) in the pathogenesis of endocardium endothelium damage (by the content of free fatty acids in it and the number of exfoliated cells) as a result of emotional and pain stress action and its influence on the background of hypercholesterolemia.&#x0D; Materials and methods of research. An electro-pulse model was used for stress reproduction. The alimentary hypercholesterolemia was simulated by keeping animals on an atherogenic diet during 2 months. To establish the role of the above-mentioned cellular structures in the mechanisms of endothelial cell damage, the following pharmacological drugs were administered to animals: β-adrenoblocker, α-adrenoblocker and Ca2+-channel blocker. The endocardium endothelium state was studied by using light microscopy, by analyzing the smears-imprints from macropreparations of ventricles by counting the number of endothelial cells in them. The content of free fatty acids was determined by radiochemical method.&#x0D; Research results. It has been shown that β-adrenoblocker and Ca2+-channel blocker significantly limit the damage of endocardium endothelium of left ventricle under the action of emotional and pain stress, and to a much lesser extent, the same effect has α-adrenoblocker. The protective effect of mentioned preparations under the action of stressor factor against the background of alimentary hypercholesterolemia significantly decreases.&#x0D; Conclusions. The obtained data, their analysis and comparison with the results of other experimental and clinical studies allow to make certain conclusions about the pathogenesis of endothelial dysfunction under emotional stress, as well as under conditions of its combination with hypercholesterolemia. In particular, an important link in the development of structural and some biochemical changes of endocardial endothelial cells is the toxic effect of catecholamines, which affect the organism’s functional systems mainly by β-adrenoreceptors (involving Ca2+ ions), to a lesser extent – by α-adrenoreceptors.&#x0D; Key words: endocardium, stress, hypercholesterolemia, adrenoreceptors, calcium.

The MARPELLA risk score for prediction of mortality in all-cause refractory cardiogenic shock treated with microaxial transvalvular pump: the MARPELLA study

Abstract Background Although Impella may serve as an alternative strategy in order to stabilize the heart function without the detrimental effects of catecholamines or to bridge the patients in definite therapies in the setting of cardiogenic shock (CS), leading to a widespread use of this device, data concerning reliable prediction or predefining which patients would benefit from the implantation of such a device are completely lacking. Purpose To evaluate and to compare the prognostic accuracy of the Acute-Physiology-And-Chronic-Health II (APACHE II), the Simplified-Acute-Physiology-Score II (SAPS II), the Sepsis-related-organ-failure-assessment (SOFA), the intra-aortic-balloon-pump (IABP), the CardShock Score in refractory CS treated with Impella 2.5/CP. Moreover, we aimed to assess the prediction-of-Cardiogenic-shock-Outcome-foR-AMI-patients-salvaGed by VA-ECMO (ENCOURAGE) and the Survival-after -Veno-Arterial-extracorporeal-membranoxygenation (VA-ECMO) (SAVE) score, though initially for VA-ECMO patients created, in patients with CS as well as to develop a new prognostic score in this setting. Methods Single center study of consecutive Impella patients with CS admitted to Cardiology department of our university, from February 2013 until December 2020. Results A total of 401 patients were included in the analysis. 31% of the patients were supported with Impella CP, whereas 153 (38,1%) patients were resuscitated prior admission. Causes of CS was acute myocardial infarction in 311 (77,5%) patients, followed by dilatative cardiomyopathy/myocarditis (11,1%) and aortic stenosis (6%). The expected mortality according to scores was: SOFA 50%, SAPS II 70%, IABP Shock 55%, CardShock 60%, APACHE II 65%, ENCOURAGE 75% and SAVE score 70%. We observed a survival of 48,9% on hospital discharge and 45,6% after 12 months follow-up. Among the traditional scores estimated, the ENCOURAGE score was the most effective predictive model of mortality outcome presenting a moderate area under curve (AUC) of 0.72, followed by the CardShock, which derived an AUC of 0,7. The SAPS II, SOFA, IABP and the SAVE scores failed to predict outcome in this setting. According to the main predictors of outcome in our population derived from univariate analysis (vasoactive score &amp;gt;31, lactate&amp;gt;4,7 mmol/l, pH&amp;lt;7,31, Creatinine&amp;gt;1,33 mg/dl, Horowitz Index&amp;lt;238, age&amp;gt;71 years and prior resuscitation) as well as the odds ratio derived from binary regression analysis on mortality, a new score, the MARPELLA score, was created. This score reached an AUC of 0.83 (Figure 1). A mortality of 37%, 62% and 83,2% was observed in the low-, intermediate and high-risk group of the MARPELLA score, respectively (Figure 2). Conclusion MARPELLA Score is a new more potent score in the setting of all-cause CS that may guide clinicians to optimize the therapy in this group of patients, outweighing the traditional CS and intensive care unit scores. Funding Acknowledgement Type of funding sources: None.

Biventricular unloading with impella and venoarterial extracorporeal membrane oxygenation in severe refractory cardiogenic shock: prognosis and implications from the combined use of the devices

Abstract Background Patients with refractory cardiogenic shock (RCS) may present with left ventricle (LV)-failure, biventricular failure or even combined cardiopulmonary failure. Mechanical support with Impella or veno-arterial membrane oxygenation (VA-ECMO) have emerged as an alternative strategy in order to stabilize the heart function without the detrimental effects of catecholamines or to bridge the patients in definite therapies. However, the selection of the appropriate MCS should be tailored according to the underlying pathophysiology and properties of the respective MCS device. Patients with Impella who initially presented with univentricular LV failure may develop additionally right ventricle (RV) dysfunction or pulmonary failure whereas patients with VA-ECMO may show signs of LV overloading, causing pulmonary edema, LV distension and thus compromising LV myocardial recovery. Purpose To present the main outcomes and predictors of survival and safety in RCS treated with Impella and VA-ECMO. Methods Single center study of consecutive patients with biventricular unloading with Impella and VA-ECMO for RCS admitted to Cardiology department of Philipps University in Marburg, Germany, from February 2013 until December 2019. The selection of the device was based on a standard algorithm (Figure 1). Results A total of 67 patients was included in the study. Mean age was 61.07±10.7 and 54 (80.6%) patients were male. Main cause of RCS was acute myocardial infarction (AMI) (74.6%), while 44 (65.7%) were resuscitated prior to admission. In 28 patients Impella was implanted first, whereas VA-ECMO was the first MCS device in 39 patients. The mean Simplified Acute Physiology Score II (SAPS II) and Sequential Organ Failure Assessment Score (SOFA) score on admission was 73.54±16.03 and 12.25±2.71, respectively, corresponding to an expected mortality of higher than 80%. Vasopressor doses and lactate levels were significantly decreased within 72 h on biventricular support (p&amp;lt;0.05 for both). Overall, 17 (25.4%) patients were discharged to cardiac rehabilitation and 5 patients (7.5%) were bridged successfully to ventricular assist device implantation, leading to a total of 32.8% survival on hospital discharge. The 6-month survival was 31.3%. Lactate &amp;gt;6 mmol/L, vasoactive score &amp;gt;100 and pH &amp;lt;7.26 on initiation of biventricular support, as well as Charlson comorbity index (CCI) &amp;gt;3 and prior resuscitation were independent predictors of survival (Figure 2). Conclusions Biventricular support with Impella and VA-ECMO in patients with RCS is feasible and efficient leading to a better survival than predicted through traditional risk scores, mainly via significant hemodynamic improvement and reduction in lactate levels. Lactate, pH and vasoactive score on initiation of biventricular support, as well as age-adjusted CCI and prior resuscitation are independent risk factors associated with mortality in this group of patients. Funding Acknowledgement Type of funding sources: None.

Quantification of cyclic AMP and cyclic GMP levels in Krebs-Henseleit solution by LC-MS/MS: Application in washed platelet aggregation samples

Cyclic Nucleotides are important in regulating platelet function. Increases in 3′5′-cyclic adenosine monophosphate (cAMP) and 3′5′-cyclic guanosine monophosphate (cGMP) inhibit platelet aggregation and are pharmacological targets for antiplatelet therapy. Here we report an improved method for determining cAMP and cGMP concentrations and, for the first time, in washed platelet supernatants by combining high-performance liquid chromatography and tandem mass spectrometry (LC-MS/MS). Characteristic peaks of the substrates, cGMP or cAMP and their internal standards were identified in negative-ion electrospray ionisation using multiple reaction monitoring. Compared with previously reported methods, the method presented here shows high precision with the lowest lower limit of quantification (LLoQ) to date (10 pg/mL). The effect of a novel catecholamine, 6-nitrodopamine, on cyclic nucleotide levels was quantified. Our results showed that this new method was fast, sensitive, and highly reproducible.

Myeloid cell-derived catecholamines influence bone turnover and regeneration in mice.

Catecholamine signaling is known to influence bone tissue as reuptake of norepinephrine released from sympathetic nerves into bone cells declines with age leading to osteoporosis. Further, β-adrenoceptor-blockers like propranolol provoke osteoprotective effects in osteoporotic patients. However, besides systemic adrenal and sympathetic catecholamine production, it is also known that myeloid cells can synthesize catecholamines, especially under inflammatory conditions. To investigate the effects of catecholamines produced by CD11b+ myeloid cells on bone turnover and regeneration, a mouse line with specific knockout of tyrosine hydroxylase, the rate-limiting enzyme of catecholamine synthesis, in CD11b+ myeloid cells (THflox/flox/CD11b-Cre+, referred to as THCD11b-Cre) was generated. For bone phenotyping, male mice were sacrificed at eight and twelve weeks of age and harvested bones were subjected to bone length measurement, micro-computed tomography, fluorescence-activated cell sorting of the bone marrow, gene expression analysis, histology and immunohistochemistry. Support for an age-dependent influence of myeloid cell-derived catecholamines on bone homeostasis is provided by the fact that twelve-week-old, but not eight-week-old THCD11b-Cre mice, developed an osteopenic phenotype and showed increased numbers of neutrophils and T lymphocytes in the bone marrow, while CCL2, IL-6, IL-4 and IL-10 mRNA expression was reduced in sorted myeloid bone marrow cells. To investigate the influence of myeloid cell-derived catecholamines on fracture healing, mice received a diaphyseal femur osteotomy. Three days post-fracture, immunohistochemistry revealed an increased number of macrophages, neutrophils and cytotoxic T lymphocytes in the fracture hematoma of THCD11b-Cre mice. Micro-computed tomography on day 21 showed a decreased tissue mineral density, a reduced bone volume and less trabeculae in the fracture callus indicating delayed fracture healing, probably due to the increased presence of inflammatory cells in THCD11b-Cre mice. This indicates a crucial role of myeloid cell-derived catecholamines in immune cell-bone cell crosstalk and during fracture healing.

Catecholamine-dependent hyperpolarization of the junctional membrane via β2- adrenoreceptor/Gi-protein/α2-Na-K-ATPase pathway

We investigated the effects of catecholamines, adrenaline and noradrenaline, as well as β-adrenoceptor (AR) modulators on a resting membrane potential at the junctional and extrajunctional regions of mouse fast-twitch Levator auris longus muscle. The aim of the study was to find which AR subtypes, signaling molecules and Na,K-ATPase isoforms are involved in the hyperpolarizing action of catecholamines and whether this action could be accompanied by changes in the pump abundance on the sarcolemma. Adrenaline, noradrenaline and specific β2-AR agonist induced hyperpolarization of both junctional and extrajunctional membrane, but the underlying mechanisms were different. In the junctional membrane the hyperpolarization depended on α2 isoform of the Na,K-ATPase and Gi-protein, whereas in the extrajunctional regions the hyperpolarization mainly relied on α1 isoform of Na,K-ATPase and adenylyl cyclase activities. In both junctional and extrajunctional regions, AR activation caused an increase in Na,K-ATPase abundance in the plasmalemma in a protein kinase A-dependent manner. Thus, the compartment-specific mechanisms are responsible for catecholamine-mediated hyperpolarization in the skeletal muscle.

Importance of catecholamine signaling in the development of platelet exhaustion after traumatic injury

BackgroundImpaired ex vivo platelet aggregation is common in trauma patients. The mechanisms driving these impairments remain incompletely understood, but functional platelet exhaustion due to excessive in vivo activation is implicated. Given platelet adrenoreceptors and known catecholamine surges after injury, impaired ex vivo platelet aggregation in trauma patients may be linked to catecholamine‐induced functional platelet exhaustion. ObjectiveTo determine the relationship of catecholamines with platelet‐dependent hemostasis after injury and to model catecholamine‐induced functional platelet exhaustion in healthy donor platelets. Patients/MethodsWhole blood was collected from 67 trauma patients as part of a prospective cohort study. Platelet aggregometry and rotational thromboelastometry were performed, and plasma epinephrine (EPI) and norepinephrine (NE) concentrations were measured. The effect of catecholamines on healthy donor platelets was examined in a microfluidic model, with platelet aggregometry, and by flow cytometry examining surface markers of platelet activation. ResultsIn trauma patients, EPI and NE were associated with impaired platelet aggregation (both p < 0.05), and EPI was additionally associated with decreased viscoelastic clot strength, increased fibrinolysis, and mortality (all p < 0.05). In healthy donors, short duration incubation with EPI enhanced platelet aggregation, platelet adhesion under flow, and increased glycoprotein IIb/IIIa activation, while weaker effects were observed with NE. Compared with short incubation, longer incubation with EPI resulted in decreased platelet adhesion, platelet aggregation, and surface expression of glycoprotein IIb/IIIa. ConclusionsThese findings suggest sympathoadrenal activation in trauma patients contributes to impaired ex vivo platelet aggregation, which mechanistically may be explained by a functionally exhausted platelet phenotype under prolonged exposure to high plasma catecholamine levels.